/* ============================================================
   FRESHMAN ENGINEERING DEPARTMENT
   MODERN RESPONSIVE NAVBAR
   Compatible with navbar.js + Bootstrap 5
   ============================================================ */


/* ============================================================
   1. NAVBAR MAIN
   ============================================================ */

#mainNav {
    position: relative;
    z-index: 1050;
    width: 100%;
    min-height: 58px;

    background: linear-gradient(
        135deg,
        #06194a 0%,
        #0b3c78 45%,
        #087e8b 100%
    );

    border: none;
    box-shadow: 0 4px 18px rgba(0, 0, 0, 0.18);

    font-family: "Segoe UI", "Inter", Arial, sans-serif;
}


/* Inner container */

#mainNav .nav-inner {
    min-height: 58px;
    display: flex;
    align-items: center;
}


/* ============================================================
   2. MAIN MENU
   ============================================================ */

#mainNav .navbar-nav {
    display: flex;
    align-items: center;
    justify-content: center;

    width: 100%;
    margin: 0 auto;
    padding: 0;

    gap: 2px;
}


/* Main menu item */

#mainNav .nav-item {
    position: relative;
}


/* Main menu links */

#mainNav .nav-link {
    position: relative;

    display: flex;
    align-items: center;
    justify-content: center;

    min-height: 58px;
    padding: 0 13px !important;

    color: #ffffff !important;

    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.15px;

    text-decoration: none;

    white-space: nowrap;

    transition:
        color 0.25s ease,
        background 0.25s ease,
        transform 0.25s ease;
}


/* Hover */

#mainNav .nav-link:hover {
    color: #ffd45a !important;

    background: rgba(255, 255, 255, 0.08);

    transform: translateY(-1px);
}


/* Active menu */

#mainNav .nav-link.active {
    color: #ffd45a !important;
}


/* Active underline */

#mainNav .nav-link.active::after {
    content: "";

    position: absolute;

    left: 15%;
    right: 15%;
    bottom: 5px;

    height: 3px;

    background: #f5c542;

    border-radius: 20px;
}


/* ============================================================
   3. DROPDOWN ARROW
   ============================================================ */

#mainNav .dropdown-toggle::after {
    margin-left: 7px;

    vertical-align: middle;

    border-top: 5px solid currentColor;
    border-right: 4px solid transparent;
    border-left: 4px solid transparent;

    transition: transform 0.25s ease;
}


#mainNav .dropdown.show > .dropdown-toggle::after {
    transform: rotate(180deg);
}


/* ============================================================
   4. FIRST LEVEL DROPDOWN
   ============================================================ */

#mainNav .dropdown-menu {
    position: absolute;

    top: calc(100% + 2px);
    left: 0;

    min-width: 220px;
    max-width: 330px;

    padding: 7px;

    margin: 0;

    background: #ffffff;

    border: 1px solid rgba(6, 25, 74, 0.10);

    border-radius: 0 0 10px 10px;

    box-shadow:
        0 12px 30px rgba(0, 0, 0, 0.18),
        0 3px 8px rgba(0, 0, 0, 0.08);

    opacity: 0;
    visibility: hidden;

    transform: translateY(8px);

    transition:
        opacity 0.20s ease,
        transform 0.20s ease,
        visibility 0.20s ease;
}


/* Bootstrap show */

#mainNav .dropdown-menu.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}


/* ============================================================
   5. MAIN DROPDOWN ITEMS
   ============================================================ */

#mainNav .dropdown-item {
    position: relative;

    display: flex;
    align-items: center;

    min-height: 38px;

    padding: 8px 13px;

    color: #243447;

    font-size: 13.5px;
    font-weight: 500;

    line-height: 1.35;

    border-radius: 7px;

    white-space: normal;

    transition:
        color 0.2s ease,
        background 0.2s ease,
        padding-left 0.2s ease;
}


/* Hover */

#mainNav .dropdown-item:hover,
#mainNav .dropdown-item:focus {
    color: #ffffff;

    background: linear-gradient(
        90deg,
        #0b3c78,
        #087e8b
    );

    padding-left: 18px;
}


/* Active dropdown item */

#mainNav .dropdown-item.active {
    color: #ffffff;

    background: #0b3c78;

    font-weight: 600;
}


/* ============================================================
   6. SUBMENU
   ============================================================ */

#mainNav .dropdown-submenu {
    position: relative;
}


/*
   Second / third / fourth level menus
*/

#mainNav .dropdown-submenu > .dropdown-menu {
    top: -7px;
    left: calc(100% + 4px);

    margin-top: 0;

    border-radius: 8px;

    opacity: 0;
    visibility: hidden;

    transform: translateX(8px);
}


/* JavaScript adds .show */

#mainNav .dropdown-submenu > .dropdown-menu.show {
    opacity: 1;
    visibility: visible;

    transform: translateX(0);
}


/* Submenu arrow */

#mainNav .dropdown-submenu > .dropdown-toggle {
    padding-right: 35px;
}


/* Right arrow */

#mainNav .dropdown-submenu > .dropdown-toggle::after {
    position: absolute;

    right: 13px;
    top: 50%;

    margin: 0;

    transform: translateY(-50%) rotate(-90deg);

    border-top: 5px solid transparent;
    border-bottom: 5px solid transparent;
    border-left: 5px solid #64748b;

    border-right: 0;
}


#mainNav .dropdown-submenu.show > .dropdown-toggle::after {
    transform: translateY(-50%) rotate(0deg);

    border-left-color: #ffffff;
}


/* ============================================================
   7. DROPDOWN DIVIDER
   ============================================================ */

#mainNav .dropdown-divider {
    margin: 6px 8px;

    border-top: 1px solid rgba(11, 60, 120, 0.12);
}


/* ============================================================
   8. LONG MENU TEXT
   ============================================================ */

#mainNav .dropdown-menu {
    overflow: visible;
}


#mainNav .dropdown-menu .dropdown-item {
    max-width: 320px;
}


/* ============================================================
   9. NAVBAR TOGGLER
   ============================================================ */

#mainNav .navbar-toggler {
    width: 44px;
    height: 40px;

    padding: 6px;

    border: 1px solid rgba(255, 255, 255, 0.45);

    border-radius: 7px;

    background: rgba(255, 255, 255, 0.08);

    box-shadow: none;
}


#mainNav .navbar-toggler:focus {
    box-shadow: 0 0 0 3px rgba(255, 213, 90, 0.25);
}


/* Custom hamburger */

#mainNav .navbar-toggler-icon {
    width: 22px;
    height: 18px;

    background-image: none;

    position: relative;

    display: inline-block;

    border-top: 2px solid #ffffff;
    border-bottom: 2px solid #ffffff;
}


#mainNav .navbar-toggler-icon::after {
    content: "";

    position: absolute;

    left: 0;
    top: 7px;

    width: 100%;
    height: 2px;

    background: #ffffff;
}


/* ============================================================
   10. DESKTOP HOVER
   ============================================================ */

@media (min-width: 992px) {

    #mainNav .nav-item.dropdown:hover > .dropdown-menu {
        opacity: 1;
        visibility: visible;

        transform: translateY(0);
    }


    #mainNav .dropdown-submenu:hover > .dropdown-menu {
        opacity: 1;
        visibility: visible;

        transform: translateX(0);
    }


    #mainNav .dropdown-submenu > .dropdown-menu {
        display: block;
    }


    #mainNav .dropdown > .dropdown-menu {
        display: block;
    }
}


/* ============================================================
   11. TABLET
   ============================================================ */

@media (min-width: 992px) and (max-width: 1250px) {

    #mainNav .nav-link {
        padding-left: 8px !important;
        padding-right: 8px !important;

        font-size: 12.5px;
    }

    #mainNav .navbar-nav {
        gap: 0;
    }

}


/* ============================================================
   12. MOBILE / TABLET
   ============================================================ */

@media (max-width: 991.98px) {

    #mainNav {
        min-height: 54px;
    }


    #mainNav .nav-inner {
        min-height: 54px;

        flex-wrap: wrap;
    }


    #mainNav .navbar-toggler {
        margin-left: auto;
    }


    #mainNav .navbar-collapse {
        width: 100%;

        max-height: calc(100vh - 60px);

        overflow-y: auto;

        margin-top: 8px;

        padding: 8px 0 12px;
    }


    #mainNav .navbar-nav {
        width: 100%;

        display: block;

        padding: 5px;

        background: rgba(255, 255, 255, 0.04);

        border-radius: 8px;
    }


    #mainNav .nav-item {
        width: 100%;
    }


    #mainNav .nav-link {
        justify-content: flex-start;

        width: 100%;

        min-height: 45px;

        padding: 10px 14px !important;

        border-radius: 7px;

        font-size: 14px;
    }


    #mainNav .nav-link.active::after {
        display: none;
    }


    /* Mobile first-level dropdown */

    #mainNav .dropdown-menu {
        position: static;

        width: 100%;
        min-width: 100%;
        max-width: none;

        margin: 3px 0 7px;

        padding: 5px;

        background: #f8fafc;

        border: none;

        border-radius: 8px;

        box-shadow: inset 0 0 0 1px rgba(11, 60, 120, 0.08);

        opacity: 1;

        visibility: visible;

        transform: none;

        display: none;
    }


    #mainNav .dropdown.show > .dropdown-menu,
    #mainNav .dropdown-menu.show {
        display: block;
    }


    /* Mobile submenu */

    #mainNav .dropdown-submenu > .dropdown-menu {
        position: static;

        width: calc(100% - 8px);

        margin-left: 8px;

        background: #eef5fa;

        box-shadow: none;

        opacity: 1;

        visibility: visible;

        transform: none;

        display: none;
    }


    #mainNav .dropdown-submenu.show > .dropdown-menu {
        display: block;
    }


    #mainNav .dropdown-item {
        min-height: 40px;

        padding: 9px 12px;

        font-size: 13.5px;
    }


    #mainNav .dropdown-item:hover,
    #mainNav .dropdown-item:focus {
        padding-left: 16px;
    }


    /* Mobile arrows */

    #mainNav .dropdown-submenu > .dropdown-toggle::after {
        right: 14px;

        transform: translateY(-50%) rotate(90deg);

        border-top: 5px solid transparent;
        border-bottom: 5px solid transparent;
        border-left: 5px solid #64748b;
    }


    #mainNav .dropdown-submenu.show > .dropdown-toggle::after {
        transform: translateY(-50%) rotate(0deg);
    }

}


/* ============================================================
   13. SMALL MOBILE
   ============================================================ */

@media (max-width: 575.98px) {

    #mainNav .nav-link {
        font-size: 13.5px;
    }


    #mainNav .dropdown-item {
        font-size: 13px;
    }


    #mainNav .dropdown-menu .dropdown-item {
        max-width: 100%;
    }


    #mainNav .navbar-collapse {
        max-height: 80vh;
    }

}


/* ============================================================
   14. SCROLLBAR
   ============================================================ */

#mainNav .navbar-collapse::-webkit-scrollbar {
    width: 6px;
}


#mainNav .navbar-collapse::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
}


#mainNav .navbar-collapse::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.35);

    border-radius: 10px;
}


/* ============================================================
   15. ACCESSIBILITY
   ============================================================ */

#mainNav a:focus-visible,
#mainNav button:focus-visible {
    outline: 2px solid #ffd45a;

    outline-offset: 2px;
}


/* ============================================================
   16. PREVENT HORIZONTAL OVERFLOW
   ============================================================ */

#mainNav,
#mainNav .navbar-collapse,
#mainNav .dropdown-menu {
    box-sizing: border-box;
}


/* ============================================================
   17. VERY WIDE SCREENS
   ============================================================ */

@media (min-width: 1400px) {

    #mainNav .nav-link {
        padding-left: 15px !important;
        padding-right: 15px !important;

        font-size: 14px;
    }

}


/* ============================================================
   18. PRINT
   ============================================================ */

@media print {

    #mainNav {
        display: none !important;
    }

}
/* ============================================================
   FIX: RIGHT-SIDE SUBMENU VISIBILITY
   Automatically opens submenu to LEFT when near screen edge
   ============================================================ */

@media (min-width: 992px) {

    /* Default: submenu opens to the right */
    #mainNav .dropdown-submenu > .dropdown-menu {
        left: calc(100% + 4px);
        right: auto;
        top: -7px;
        transform: translateX(8px);
    }

    /* When JavaScript detects insufficient right space */
    #mainNav .dropdown-submenu.submenu-left > .dropdown-menu {
        left: auto;
        right: calc(100% + 4px);
        transform: translateX(-8px);
    }

    #mainNav .dropdown-submenu.submenu-left > .dropdown-menu.show {
        transform: translateX(0);
    }

    /* Arrow points LEFT */
    #mainNav .dropdown-submenu.submenu-left > .dropdown-toggle::after {
        transform: translateY(-50%) rotate(180deg);
    }

    #mainNav .dropdown-submenu.submenu-left.show > .dropdown-toggle::after {
        transform: translateY(-50%) rotate(180deg);
    }
}